Comments requested for a couple of Ada-Comments submissions

[Shark8 <OneWingedShark@gmail.com>]

On 11-Jul-14 15:24, Randy Brukardt wrote:
> This is roughly what GNAT is doing, and I think this is horrible. An
> attribute is some sort of function, and it would never be possible to write
> a function that works like this. I don't want more magic in the language if
> we can help it. Moreover, this ought to have the semantics of an aggregate
> (vis-a-vis temporaries, build-in-place, and the like), and as such it ought
> to look like an aggregate.

I agree -- I think this should not be an attribute, nor the addition of 
new keywords.

Perhaps something along the lines of Extension Aggregates [ref 4.3.2].
-- Reminder --

extension_aggregate ::=
     (ancestor_part with record_component_association_list)

ancestor_part ::= expression | subtype_mark

-- New Syntax --
partial_aggregate ::=
     (modified_part with all others => <>)

where modified_part denotes the portion being updated, in list/alternate 
form...
-- Given record a containing integer fields B, C, D:
A:= (B => 1, D => 2 with all others => <>);
-- Given bit-array A with indices 1..16:
A:= (1..4 => 1, 9..16 => 0 with all others => <>);

It obviously wouldn't work on a unconstrained array-type initialization, 
where the variable would try to get its constraints from the right-hand 
side, but considering the intended use I don't see why that would be a 
bad thing.
Just an idea.